Lipase-catalyzed preparation of human milk fat substitutes from palm stearin in a solvent-free system.

Human milk fat substitutes (HMFSs) were synthesized by lipozyme RM IM-catalyzed acidolysis of chemically interesterified palm stearin (mp = 58 °C) with mixed FAs from rapeseed oil, sunflower oil, palm kernel oil, stearic acid, and myristic acid in a solvent-free system. Response surface methodology (RSM) was used to model and optimize the reactions, and the factors chosen were reaction time, temperature, substrate molar ratio, and enzyme load. The optimal conditions generated from the models were as follows: reaction time, 3.4 h; temperature, 57 °C; substrate molar ratio, 14.6 mol/mol; and enzyme load, 10.7 wt % (by the weight of total substrates). Under these conditions, the contents of palmitic acid (PA) and PA at sn-2 position (sn-2 PA) were 29.7 and 62.8%, respectively, and other observed FAs were all within the range of FAs of HMF. The product was evaluated by the cited model, and a high score (85.8) was obtained, which indicated a high degree of similarity of the product to HMF.

Comparative analysis of lipid composition and thermal, polymorphic, and crystallization behaviors of granular crystals formed in beef tallow and palm oil.

Six rectangular block all beef tallow (BT)-based and all palm oil (PO)-based model shortenings prepared on a laboratory scale, respectively denoted BTMS and POMS, were stored under temperature fluctuation cycles of 5-20 °C until granular crystals were observed. The lipid composition and thermal, polymorphic, and isothermal crystallization behaviors of the granular crystals and their surrounding materials separated from BTMS and POMS, respectively, were evaluated. The changes of nanostructure including the aggregation of high-melting triacylglycerols (TAGs) and polymorphic transformation from ß' form of double chain length structures to complicated crystal structures, in which the ß and ß' form crystals of triple and double chain length structures simultaneously coexist, had occurred in granular crystals compared with surrounding materials, whether in BTMS or in POMS. Consequently, a slower crystallization rate appeared in granular crystal parts of both model shortenings noted above, which would yield larger and fewer crystals indicated by the Avrami model analysis that would further aggregate to form large granular crystals.

[Analysis of the volatile oils chemical constituents of roots of Actinidia deliciosa].

OBJECTIVE: To analyze the volatile oils chemical constituents of roots of Actinidia deliciosa. METHODS: The volatile oils fraction of roots of Actinidia deliciosa. were extracted by water vapor distilling, and then the constituents were separated and identified, by GC-MS. RESULTS: 16 compounds were identified, accounting for 89.37% of all quantity. CONCLUSION: The principal volatile oils chemical constituents are Phenol, 2,4-bis(1,1-dimethylethl)-; 2-Propenoic acid, 3-(4-methox yphenyl)-, ethyl ester; 9-Octadecenoic acid (Z)-, methyl ester; Cyclotetrasiloxane, octamethyl-.